Hi,
Sorry I should have advertised that i use a complete custom controller that i made from scratch. (you can have a glimpse here: How to deal with motorised faders - #6 by thomas_martin)
But in essence it’s just 3 MCU plus an add-on that is more-or-less a Nektar CS12.
Nuendo 12 introduced a new way of interfacing a MIDI controller with Nuendo called MIDI Remote. Nektar CS12 takes great advantage of it because it allows deeper integration than any MIDI protocol before thanks to an evolving API.
There are scripts written by users that should be compatible with most MCU clones (or originals). In the end they all use the same set of MIDI messages. You might want to try one of them and see if it fits your workflow because MIDI Remote is ALWAYS auto-banking (which is a big flaw to me, i hate auto-banking).
For example, there is this one or this one or maybe this one and there may be more…
Just don’t forget to disconnect you controllers from the mackie control instances in the studio setup.
Yes, that is probably true, to each is own ergonomics.
To summarize my way of dealing with 250+ tracks (i Mix cartoon shows mostly):
My template has 16 tracks of dialogues at the top and then all the buses and Fxs. Therefore with 24 faders, I can have most of them in front of my eyes all the time.
When i want to automate another track , i use my 25th fader which controls the ‘selected track(s)’ (Q-link option), in fact i have a display/control of the full selected channel strip. Also I set the preference “track selection follows event selection” ON.
Just an example: let’s say a big robot is crossing the screen from left to right. I can select all its related clips (footsteps, foleys, fxs, voice, whatever), this will in turn select the related tracks. Now I just have to grab my panner with my right hand and my fader with the left one and all the robot’s related sounds will be following my movements.
And the best is i still have all my most important channels right there in front of me and didn’t lose time banking back and forth. 
But again, to each is own…
Hope this helps,
Thomas